/Engine/Source/Runtime/Core/Public/Experimental/Async/AwaitableTask.h
TheTPromiseVTableDummyis used with empty handles, this allows us to always call the virtual interface without nullpointer checks validation for launching and getting the result of empty taskhandles is done as well.
template<typename ReturnType> class TPromiseVTableDummy : public [AwaitableTask_Detail::TPromiseVTableBase< ReturnType >](API\Runtime\Core\Experimental\Async\TPromiseVTableBase)